Red Hat Enterprise Linux 5 (RHEL 5) has been cloned. And barely a month after its release.

The release of the free, community-based CentOS 5 Enterprise Linux so soon after the RHEL 5 release is hardly a surprise; the same thing happened with RHEL 4 two years ago. Nor does Red Hat consider CentOS a competitor, but rather a distribution that fills a need. The company also said CentOS will help it grow its business.

"From the technology side, CentOS broadens the customer base for Red Hat
Enterprise Linux technology," Nick Carr, a product marketing director for
RHEL, told internetnews.com. "They are active in the mailing list, and
from an engineering viewpoint they certainly assist us in finding problems
in the product."

What CentOS is doing by cloning RHEL is something that takes advantage of
one of the fundamental tenets of open source software: it is free and can be modified, copied and redistributed. Red Hat by definition and by practice is an open source vendor and its RHEL code is freely available on Red Hat's servers.

But there are restrictions. CentOS cannot use the Red Hat trademarks and cannot claim it is an RHEL distribution. Oracle is doing the same thing with Oracle Enterprise Linux (OEL), though OEL five, for which paid support is available, is not yet out.

At a core technology level, CentOS 5 is almost identical to RHEL 5, though
for Red Hat, it's about more than just the operating system.

"For us it's about providing a complete solution, not just in the operating
system but also moving up the stack," Carr said. "It's not an issue of
taking a bunch of bits burning them on a CD, throwing them over the wall and
saying have a good time."

"That's not the business that we're in; the operating system is merely a
component."

Carr argued that Red Hat customers don't want to do deployments in the
blind. They need the professional support and certification the Red Hat
provides since their usage is often business critical.

"It's the people that succeed with open source that value the subscription
with Red Hat," Carr said.

Carr also noted that there are CentOS users who decide to move to Red Hat
after they've been running CentOS for a period of time.

"We certainly get CentOS customers who will see the value of the Red Hat
model when what they are deploying becomes more and more critical to their
infrastructure," Carr noted.

A key differentiator, according to Carr, is also the fact that Red Hat offers
seven years of support for its RHEL release. For example, Red Hat is still
doing fixed for RHEL version 2 which came out five years ago. Typically that
length of support does not exist in the community.

"They'll just say 'upgrade to the latest release,'" Carr said. "Real
commercial customers don't do that, they often times stay with a release of
the life of the hardware on which the release is installed."

RHEL 5 is tested on major vendor platforms. Carr noted
that if something is wrong and you've got to call IBM for example they'll
understand what you're running with RHEL and it's supported.

"That's not to say that what CentOS offers to customers isn't of great
value to customers," Carr said. "It's just not the same as what Red Hat
is offering."